"Been taking the high road for a long time.. I almost gave up. But I can finally see something on the horizon up there!! Wait!! Could it be?! Yep!! It’s karma!!" Shelton tweeted after multiple outlets reported Lambert began dating married Turnpike Troubadours front man, Evan Felker.

Evan Felker reportedly began dating Miranda Lambert while he was married. (Getty)

But according to Lambert's ex-boyfriend Jeff Allen, Shelton is not as innocent as he's trying to seem.

Allen tweeted and deleted a post calling out Shelton for romancing Allen's then-girlfriend Lambert while Shelton was still married to his first wife, Kaynette Williams, in 2006.

"You know, I’ve always given you the benefit of the doubt and chalked it up to just being human, but you must be one arrogant SOB to pop off something like this, when I know damn good and well you were cheating on your wife and Miranda was cheating on me when you two started up," Allen wrote in a since-deleted tweet, according to Us Weekly.

"I kept my mouth shut for 13 years. Sorry, his karma tweet rubbed me wrong. All of this is pointless," he added.

Allen told RadarOnline.com, "I’m sure Miranda did [Blake] dirty just like she did me, but he wasn’t thinking about me when he was cheating with her, so I don’t know why he thinks it's karma."

He added that he does not harbor bad feelings toward Lambert and said she "was a loving, caring person and a good girlfriend."

Reps for Lambert and Shelton did not return Fox News' requests for comment.

It's been reported that Lambert and Shelton's romance began as an affair but both singers have denied this in the past. They became engaged in May 2010 and married a year later in Texas. The country singers announced their divorce after four years of marriage in July 2015.